This invention relates to an operating device for an electric hoist whose raising or lowering speed is easily changed from low to high speed and vice versa by two-step push-buttons and the low and high speeds are simply controlled in low and high speed ranges.
The term "hoist" as used herein is intended to designate means having a DC motor for lifting an object, inclusive a chain block.
An operating device for an electric hoist such as an electric chain block has been widely used. With such a hitherto used operating device, a control box is connected to a cable depending from a main body of the electric hoist and is provided with push-button switches for raising and lowering operations and a variable resistor for adjusting raising and lowering speeds.
In raising or lowering an object at an appropriate speed by a hoist having such an operating device, an operator is pressing either of the push-button switches by a finger of his one hand which grips the control box and at the same time he operates the variable resistor by his other hand for adjusting the hoisting speed. Therefore, the operation of the device is very troublesome.